This invention relates to a method of obtaining antibodies specific to a population of T lymphocytes (T cells, TCL) restricted by V.beta. gene usage, antibodies thus obtained and methods of use thereof.
More than 95% of all T cells have a cell surface receptor designated the "T-cell receptor" (hereinafter, "TCR"). For a review of T cell ontogeny, see Moyer and Reinherz, "T Lymphocytes: Ontogeny, Function, and Relevance to Clinical Disorders", N. Engl. J. Med., 317:1136-1142 (1987). TCR consists of a clonotypic Ti .alpha.-.beta. heterodimer with an apparent molecular weight (Mw) of 90 kD and a monomorphic T3 molecule containing five subunits (.gamma., .delta., .zeta., .epsilon., and .eta.). The .gamma. subunit has an apparent Mw of 25 kD, the .delta. and .epsilon. subunits each have an apparent Mw of 20 kD, the .zeta. subunit has an apparent Mw of 16 kD, and the .eta. subunit an apparent Mw of 22 kD. All five receptor subunits are transmembrane proteins. As is the case with antigen-binding heavy and light chains of immunoglobulin proteins, TCR .alpha. and .beta. proteins contain both variable (hereinafter "V") and constant (hereinafter "C") regions. For a review of immunoglobulin proteins and gene usage, see Lewin, Genes III, John Wiley & Sons, Inc. pp. 642-653 (1987), which is incorporated herein by reference.
It appears that the Ti subunits form a binding site for antigen and the major histocompatibility complex (hereinafter "MHC") through interaction of their V domains. Antigen recognition is important for activation of both cytotoxic effector T cells and immunoregulatory T cells. Cytotoxic T cells lyse specific target cells, including tumor cells and virus-infected cells, whereas immunoregulatory T cells induce or suppress the cells of the immune system either directly or indirectly through lymphokines.
Analyses of many of the cDNA nucleotide sequences encoding a variety of .beta. chains have led to the recognition of structural similarity between genes encoding .beta. chains and genes encoding immunoglobulins. Thus, genes encoding .beta. chains contain V, constant (C), joining (J) and diversity (D)-like elements The present invention is concerned with the V region of the chain, hereinafter termed V.beta.. In humans, approximately 57 V.beta. genes are known to exist in the Ti .beta. locus on chromosome 7 at 7q35 Robinson, "The Human T Cell Receptor .beta.-chain Gene Complex Contains at Least 57 Variable Gene Segments", J Immunol , 146:4392-4397 (1991)
T cell proliferation requires the interaction of the Ti complex with antigen and interleukin-2 (hereinafter "IL-2"). Although resting T cells express no receptors for IL-2; after the T cell receptors are activated by antigen and MHC, induction of IL-2 receptors occurs within hours The activation also leads to endogenous induction and secretion of IL-2, DNA synthesis and cell mitosis.
Various disease states and physiological disorders are associated with T cell dysfunctions. These disorders, are characterized by a particular subset, or restricted population, of T cells which are thought to be responsible for the dysfunction The restricted population is recognized by its expression of only one or a few related types of TCR and can be monitored by the type of V.alpha. and/or V.beta. gene expressed. A restricted set of T cells is one in which the T cells express one or a few common V genes but are otherwise dissimilar By comparison, a clonal population of T cells, such as may be derived from a tumor, is a population of T cells that are the progeny of a single cell and are hence virtually identical.
Disorders thought to be caused by T cell dysfunctions include but are not limited to various autoimmune diseases such as systemic lupus erythematosus multiple sclerosis, myasthenia gravis, diabetes mellitus, and various forms of arthritis such as rheumatoid arthritis. These dysfunctions are characterized by the expansion of a restricted T cell population that expresses one or a few V.beta. genes from a V.beta. family. Different patients express a single V.beta. but not necessarily the same V.beta. gene as another patient. For instance, expanded T cell populations from MS patients express one of the V genes from the related group of V.beta.12, V.beta.13, V.beta.14, V.beta.15 and V.beta.17. Several methods of therapy have been proposed based on eliminating or blocking the T cell population responsible for a dysfunction. For review see Janeway, "Immunotherapy by Peptides" Nature 341:482-483 (1989); and Hashim et al., "Antibodies for V.beta.8 Receptor Peptide Suppress Experimental Autoimmune Encephalomyelitis", J. Immunol., 144:4621-4627 (1990), which are incorporated herein by reference.
There is considerable evidence of selective TCR V.beta. gene usage among rodent T cells which mediate a number of experimental autoimmune diseases. For example, in experimental allergic encephalomyelitis (EAE), V.beta.8.2.sup.+ T cells play a central role. In five different strains of rats, encephalitogenic T cell clones and hybridomas, reactive against myelin basic protein (MBP) peptide fragments, were found to be uniformly V.beta.8.2.sup.+. Burns et al., "Both Rat and Mouse TcRs Specific for the Encephalitogenic Determinant of MBP use Similar V.alpha. and V.beta. Chain Genes Even Though the MHC and Encephalitogenic Determinants Being Recognized are Different", J. Exp. Med., 169:27 (1989). Similarly, V.beta.8.2 is expressed on over 85% of T cells reacting to the encephalitogenic MBP peptide in strains of mice susceptible to EAE. Acha-Orbea et al., "Limited Heterogeneity of T Cell Receptors From Lymphocytes Mediating Autoimmune Encephalomyelitis Allows Specific Immune Intervention" Cell 54:563 (1988); and Urban et al , "Restricted Use of T Cell Receptor Genes in Murine Autoimmune Encephalomyelitis Raises Possibilities for Antibody Therapy", Cell, 54:577 (1988). The mouse V.beta.8 gene family products are homologous to the human V.beta.12, V.beta.13, V.beta.14, V.beta.15 and V.beta.17 gene products.
The in vivo administration of mAb specific for V.beta.8.2 has been shown to both protect mice from the development of EAE induced by a subsequent challenge with MBP, and to ameliorate the clinical course of EAE in mice already affected. Acha-Orbea et al. (1988). It has also been found that EAE can be vaccinated against. In this case, the anti-T cell response is mediated by another set of T cells Lohse et al,. "Control of Experimental Autoimmune Encephalomyelitis by T Cells Responding to Activated T Cells", Science, 244:820-824 (1989).
In another animal disease model, collagen-induced arthritis, T cells reactive against type II collagen which are capable of transferring arthritis to naive syngeneic mice are virtually all V.beta.8.2.sup.+ Banerjee et al., "Possible Role of V.beta. T Cell Receptor Genes in Susceptibility to Collagen-Induced Arthritis in Mice", J Exp Med , 167:832 (1988). These observations suggest that expression of the V.beta.8.2 gene product may be associated with an autoimmune T cell pool in rodents, for instance, T cells derived from the CD4.sup.- CD8.sup.- V.beta.8.2 expressing thymocyte subpopulations. Fowlkes et al., "A Novel Population of T Cell Receptor .alpha..beta. Bearing Thymocytes Which Predominantly Express a Single V.beta. Gene Family", Nature, 329:251 (1987); Shortman et al., "Mouse Strain Differences in Subset Distribution and T Cell Antigen Receptor Expression Among CD4.sup.- CD8.sup.- Thymocytes", Immunol. Cell Biol., 66:423 (1988); and Takahama et al., "Phenotype, Ontogeny, and Repertoire of CD4.sup.- CD8.sup.- T Cell Receptor .alpha..beta..sup.+ Thymocytes: Variable Influence of Self-Antigens on T Cell Receptor V.beta. Usage", J. Immunol., 146:1134 (1991).
Recently, it has been possible to determine the TCR gene usage of a population of T cells. Bertness et al., "T cell Receptor Gene Rearrangements as Clinical Markers of Human T cell Lymphomas", N. Engl. J. Med., 313:534-538 (1985). Such determinations have relied on anticlonotypic antibodies directed at epitopes found on V domains of TCR and cDNA probes that detect clone-specific DNA rearrangements. However, the availability of anticlonotypic antibodies and cDNA probes has been limited to the availability of naturally occurring clonal populations of T cells such as from tumors. This drawback renders these methods less clinically applicable than would be the case if a wide variety of antibodies were available to the full range of TCR V gene products associated with T cell dysfunctions. This is particularly important in T cell dysfunctions which are characterized by restricted rather than clonal populations of T cells. It would be useful to have a method of obtaining antibodies specific for the protein products of the TCR V gene families for the purposes of diagnoses and therapeutics of various disorders related to T cell dysfunctions.